Amanda Knox told Good Morning America that she "couldn't believe what I was hearing" on Thursday when she watched an Italian court declare her guilty of murder a second time.
"It really hit me like a train," Knox said of the verdict and 28-year prison sentence. "I did not expect this to happen. I really expected so much better from the Italian justice system. They found me innocent once before."
Knox already spent four years in an Italian prison for the murder of her English roommate Meredith Kercher in 2007. She was freed in 2011 after an appeals court threw out the conviction, but Italy's supreme court ordered the case be retried. On Thursday, the court found Knox guilty and sentenced her to 28 years and six months in prison.
During the exclusive GMA interview Friday morning, Knox said she wasn't done fighting yet. "I will never go willingly back to the place ... I'm going to fight this to the very end. It's not right and it's not fair."
"This is an experience that I have to testify to, that really horrible things can happen and you have to stand up for yourself," Knox said, holding back tears.
Her former boyfriend Raffaele Sollecito was also found guilty and sentenced to 25 years. "He is vulnerable and I don't know what I would do if they imprisoned him," Knox said. "It's maddening."
Knox also revealed that she sent a letter to her lawyer addressed to Kercher's family. "It's in the mail. Mainly I just want them to know that I really understand that this is incredibly difficult, that they've also been on this never-ending thing, and when the case has been messed up so much, like, a verdict is no longer consolation for them," she said.
Watch Knox's full interview below:See more US News from ABC|ABC World News